Configuration Mechanism; Type 0 Configuration Translation - Freescale Semiconductor MPC5200B User Manual

Functional Description
Table 10-7. XLB bus to PCI Byte Lanes for Memory
A TSIZ
[29:31] [0:2]
0
011 101 --
000 110 OP2 OP3 OP4 OP5 OP6 OP7
001 110 --
010 110 --
000 111 OP1 OP2 OP3 OP4 OP5 OP6 OP7
001 111 --
000 000 OP0 OP1 OP2 OP3 OP4 OP5 OP6
a
The byte lane translation will be similar for other types of transactions. However, the PCI address may be different
Section 10.4.1.5,
as explained in
10.4.4.2

Configuration Mechanism

In order to support both Type 0 and Type 1 configuration transactions, MPC5200B provides the 32 bit Configuration Address Register (CAR),
located at module address 0x1F8. The register specifies the target PCI bus, device, function, and configuration register to be accessed. A read
or a write to the MPC5200B window defined as PCI I/O space, in PCIIWCR, causes the host bridge to translate the access into a PCI
configuration cycle if the enable bit in the Configuration Address Register is set and the device number does not equal 0b1_1111. For space
to be defined as I/O space, the accessed space (one of the initiator Windows) must be programmed as I/O, not memory.
Initiator Window Configuration Register PCIIWCR(RW) —MBAR +
The format of the Configuration Address Register is shown in
0x0DF8. When MPC5200B detects an access to an I/O Window, it checks the enable flag and the device number in the
—MBAR +
Configuration Address Register. If the enable bit is set, and the device number is not 0b1_1111, the MPC5200B performs a configuration cycle
translation function and runs a configuration read or configuration write transaction on the PCI bus. The device number 0b1_1111 is used for
performing interrupt acknowledge and Special Cycle transactions. See
10.4.4.2.4, Special Cycle Transactions
0 configuration cycle transaction is performed. If the bus number indicates a remote PCI bus, MPC5200B performs a Type 1 configuration
cycle translation. If the enable bit is not set, the access to the Configuration Window is passed through to the PCI bus as a I/O space transaction
at the internal address (window translation applies).
Note that the PCI data byte enables (C/BE[3:0]) are determined by the size access to the Window.
10.4.4.2.1

Type 0 Configuration Translation

Figure 10-7 shows the Type 0 translation function performed on the contents of the Configuration Address Register to the AD[31:0] signals
on the PCI bus during the address phase of the configuration cycle (only applies when the Enable bit in the Configuration Address Register
is set).
10-54
XL bus
Data Bus Byte Lanes
1 2 3 4
-- -- OP3 OP4 OP5 OP6
OP2 OP3 OP4 OP5 OP6 OP7
-- OP2 OP3 OP4 OP5 OP6
OP1 OP2 OP3 OP4 OP5 OP6
Addressing.
Section 10.3.2.12, Configuration Address Register PCICAR (RW)
for more information. If the bus number corresponds to the local PCI bus (bus number = 0x00), a Type
MPC5200B Users Guide, Rev. 1
a
Transactions (continued)
AD
[2:0] [3:0]
5 6 7
OP7 000 0111
100 0000
-- -- 000 0000
100 1100
-- 000 0001
100 1000
OP7 000 0011
100 0000
-- 000 0000
100 1000
OP7 000 0001
100 0000
OP7 000 0000
100 0000
0x0D80.
Section 10.4.4.2.3, Interrupt Acknowledge Transactions
PCI Bus
BE
31:2 23:1
15:8
4 6
OP3 -- --
OP7 OP6 OP5
OP5 OP4 OP3
-- -- OP7
OP4 OP3 OP2
-- OP7 OP6
OP3 OP2 --
OP7 OP6 OP5
OP4 OP3 OP2
-- OP7 OP6
OP3 OP2 OP1
OP7 OP6 OP5
OP3 OP2 OP1
OP7 OP6 OP5
Section 10.3.2.8,
Freescale Semiconductor
7:0
--
OP4
OP2
OP6
--
OP5
--
OP4
OP1
OP5
--
OP4
OP0
OP4
and Section